## Dependency Injection { #dependency-injection }

Using `BackgroundTasks` also works with the dependency injection system, you can declare a parameter of type `BackgroundTasks` at multiple levels: in a *path operation function*, in a dependency (dependable), in a sub-dependency, etc.

이것을 해결하는 일은 **FastAPI**가 알아서 처리합니다.

## 첫 번째 의존성 "dependable" { #first-dependency-dependable }

다음과 같이 첫 번째 의존성("dependable")을 만들 수 있습니다:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

이 의존성은 선택적 쿼리 파라미터 `q`를 `str`로 선언하고, 그대로 반환합니다.

매우 단순한 예시(그다지 유용하진 않음)이지만, 하위 의존성이 어떻게 동작하는지에 집중하는 데 도움이 됩니다.

## 두 번째 의존성 "dependable"과 "dependant" { #second-dependency-dependable-and-dependant }

你可以建立具有「子相依」的相依項。

它們可以按你的需要，層級任意加深。

**FastAPI** 會負責解析它們。

## 第一個相依項 "dependable" { #first-dependency-dependable }

你可以建立第一個相依項（"dependable"）如下：

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

它宣告了一個可選的查詢參數 `q`（型別為 `str`），然後直接回傳它。

這很簡單（不太實用），但有助於我們專注於子相依如何運作。

## 第二個相依，同時是 "dependable" 也是 "dependant" { #second-dependency-dependable-and-dependant }

接著你可以建立另一個相依函式（"dependable"），同時它也宣告了自己的相依（因此它同時也是 "dependant"）：

  <dependencies>
    <dependency>
      <groupId>org.apache.maven.its</groupId>
      <artifactId>maven-core-it-support</artifactId>
      <version>1.3</version>
      <scope>runtime</scope>
      <exclusions>
        <exclusion>
          <groupId>commons-lang</groupId>
          <artifactId>commons-lang</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

      <url>file://dummy</url>
    </repository>
  </repositories>
  <dependencies>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t06-b</artifactId>
      <version>1.0</version>
      <type>jar</type>
      <scope>compile</scope>
    </dependency>
  </dependencies>

      <url>file://dummy</url>
    </repository>
  </repositories>
  <dependencies>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t07-b</artifactId>
      <version>1.0</version>
      <type>jar</type>
      <scope>compile</scope>
    </dependency>
  </dependencies>

    simple request and response logging. It may be configured to log headers and
    bodies for debugging. It requires this Maven dependency:

     ```xml
     <dependency>
       <groupId>com.squareup.okhttp</groupId>
       <artifactId>logging-interceptor</artifactId>
       <version>2.6.0</version>
     </dependency>
     ```

    Configure basic logging like this:

    ```java

    groups:
      github-actions:
        patterns:
          - "*"

  - package-ecosystem: docker
    directory: /ci/devinfra/docker_windows
    schedule:
      interval: monthly
    ignore:
      - dependency-name: "*"
        update-types: ["version-update:semver-major", "version-update:semver-minor"]

  - package-ecosystem: docker
    directory: /tensorflow/tools/gcs_test
    schedule:
      interval: monthly

    }

    public boolean isResolved() {
        return children != null;
    }

    /**
     * Test whether the node is direct or transitive dependency.
     *
     * @return whether the node is direct or transitive dependency
     */
    public boolean isChildOfRootNode() {
        return parent != null && parent.parent == null;
    }

    public Iterator<ResolutionNode> getChildrenIterator() {

     *
     * @return {@code true} if the dependency management information should be retrieved, {@code false} otherwise.
     */
    boolean isResolveManagedVersions();

    /**
     * Enables/disables resolution of the dependency management information.
     *
     * @param resolveManagedVersions {@code true} if the dependency management information should be retrieved, {@code